Asymptomatic Cases Complicate the Containment of Coronavirus

SARS-CoV-2, the biological pathogen that causes the COVID-19 disease, is a vicious virus.

While much remains to be learned, the new coronavirus seems to
be more infectious than the annual flu and possibly more deadly. The
unbelievable daily growth in the global confirmed case count speaks for itself.

Indeed, confirmed cases of COVID-19 across the globe now
exceed 1 million cases–not
to mention the death toll that continues to rise.

But that’s not the end of this pathogen’s perfidy.

Over the past few weeks, an assortment of new studies have
shown that asymptomatic carriers—those who are infected with the virus and
“shedding” (or spreading) it, but don’t show any symptoms—may be driving the
spread of the disease.

In other words, people who are sick with COVID-19 may be
moving around communities unwittingly, rather than staying at home, because
they don’t realize they’re ill and potentially contagious to others.

In an interview Monday,
Dr. Robert Redfield, director of the Centers for Disease Control and Prevention,
noted that “as many as 25%” of infected patients don’t display any symptoms.

By Friday evening, the
CDC and the White House’s coronavirus task force had endorsed the public’s wearing of nonmedical cloth face coverings–including masks–to
help address this concern, especially when social distancing is difficult.

The new recommendation shouldn’t
threaten the supply of protective masks for health care workers.

Elsewhere, a study of
roughly 700 infected passengers aboard the Diamond Princess cruise ship estimated
that 18% of the cases were asymptomatic. Yet one of the study’s authors noted that the
percentage of asymptomatic cases actually could be higher.

Results from diagnostic tests on Japanese evacuees from Wuhan,
China, where the new coronavirus originated, show similar findings. According
to a study by
Japanese scientists, nearly 31% of confirmed cases didn’t show any symptoms.

Another significant finding involves lab testing in Iceland.

The island nation has tested a larger percentage of its
population for COVID-19 than any other nation—nearly 5%. These efforts have
focused on the broader population, not just patients with moderate to severe

Thus far, about 50% of those who tested positive in Iceland haven’t
displayed any of the tell-tale flu-like symptoms.

Although scientists have yet to nail down exactly what
percentage of coronavirus cases are asymptomatic, the reality is that spread of
the disease by those without symptoms is a serious concern.

Indeed, despite the ongoing development of therapeutics,
anti-virals, vaccines, and serological
(antibody) testing
, concerns regarding asymptomatic transmission provide
a compelling case for the administration’s “stop the spread” regimen of social

The White House last weekend extended the president’s coronavirus
through at least April 30. The “30 Days to Stop the Spread”
campaign is another critical step in our battle with COVID-19.

But few disagree that social distancing—really physical
distancing–is our best chance to slow or stop the spread, especially given the
limited weapons we currently have available in our anti-viral arsenal

The idea of asymptomatic transmission is bad news, but the
good news is that we know more now about our invisible enemy than we knew

The more we know about the virus, the more efficiently and effectively we’ll wage this war.

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